One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of figuring out when you can plant polygonums is to refer to the USDA zone info for La Grande.

Planting Calendar for Polygonums

Frost tolerance for polygonums:	Not tolerant of frost.
When to plant:	After the last frost.

Polygonums do not do well in cold weather which tells us that you really should wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant polygonums in La Grande is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant polygonums and expect a good harvest is probably August. If you wait any later than that and your polygonums may not have a chance to fully mature. You can get started a few weeks earlier by starting your polygonums indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in La Grande. In the coldest months of winter you should expect an average low temperature of -5°F.

Always keep in mind that USDA zone info for La Grande may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in La Grande you get surprised by a frost after April 15 so make sure that you are ready to cover your polygonums if you have a surprise late frost.

USDA Zone Info for La Grande

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in La Grande

You may be interested in your other planting guides for La Grande.